<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>画色子</title>
    <style>
        .outer {
            width: 400px;
            height: 400px;
            border: 2px solid purple;
            border-radius: 45px;
            display: flex;
            justify-content: space-between;
        }
        
        .item {
            width: 100px;
            height: 100px;
            background-color: hotpink;
            border-radius: 100%;
        }
        .item:nth-child(2) {
            align-self: center;
        }
        .item:nth-child(3) {
            align-self: flex-end;
        }
    </style>
</head>

<body>
    <div class="outer">
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
    </div>
</body>

</html>